In an automatic analyzer including a means for installing samples in a rack and so on and conveying the samples to an analysis section, when emergency samples are installed in the analyzer, it is desired that the analysis is started in preference to samples of normal patients. In response to this, an automatic analyzer including a buffer for evacuating samples waiting for analysis is known, in which samples waiting for analysis are evacuated to the buffer when the rack in which the emergency samples are loaded is inputted, thereby preferentially starting the analysis of the emergency sample rack in preference to racks in the buffer.
When the distance from the buffer to a sample dispensing position is long, it is common that plural racks are conveyed on a conveyance path from the buffer to the sample dispensing position so as to sequentially analyze samples. However, when many racks exist on the conveyance path to the sample dispensing position in the case where the emergency sample rack is inputted, the analysis of the emergency samples are started after all samples on the conveyance path are analyzed, therefore, the analysis of the emergency samples will be delayed. In order to preferentially convey the emergency samples installed in the analyzer to the sample dispensing position, it is necessary to perform processing of returning plural racks in which samples have not been dispensed to the buffer again.
However, the same route is used for carrying-in and carrying-out in the automatic analyzer in which the buffer and the sample dispensing position are connected by one route, therefore, a waiting time occurs in the control of returning the racks to the buffer in the case where any of transfer controls in rack transfer from a rack input section to the buffer, rack transfer from the buffer to a rack storage section and rack transfer from the butter to the sample dispensing position overlaps the timing of rack transfer from the sample dispensing position to the buffer. In particular, in the automatic analyzer in which racks are conveyed from one buffer to plural different analysis sections, the rack transfer control between the buffer and the sample dispensing position is increased, therefore, it is highly likely that racks in a standby state in which samples have not been dispensed are difficult to immediately return to the buffer even when the emergency sample rack is inputted.
In response to the above, in a sample conveying system for processing samples before being analyzed by the analyzer, there is disclosed, in PTL 1, a method of limiting the number of racks to be carried in when the racks inputted into the system are conveyed to the conveyance path for immediately starting the processing of emergency samples.